## Summary
Extract shared reader utilities (`ReaderUtils.h`) to reduce duplication
across `EpubReaderActivity`, `TxtReaderActivity`, and (upcoming)
`MarkdownReaderActivity`.
Utilities extracted:
- `applyOrientation()` — orientation switch logic
- `detectPageTurn()` — page navigation input detection
- `renderAntiAliased()` — grayscale anti-aliasing pass
- `displayWithRefreshCycle()` — refresh mode cadence
- `GO_HOME_MS` — back button timing constant
## Impact
Flash: 32 bytes saved (6006441 → 6006409 bytes). Minimal immediate gain,
but meaningful once markdown reader and future reader types share these
functions.
Code quality: Eliminates ~100 lines of duplicated logic spread across
multiple files. All readers now follow the same patterns for
orientation, input handling, and rendering.
## Rationale
This refactor is preparation for markdown support, which requires
identical input and rendering logic. Instead of copy-pasting these
patterns a third time, all readers now share a single, tested
implementation. Future reader types can reuse `ReaderUtils` without
duplication.
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## AI Usage
Did you use AI tools to help write this code? YES Claude extracted the
code, under my guidance. Tested on my device and seems to work fine.
jpirnay